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   sfdisk    ( 8 )

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INPUT FORMATS

sfdisk supports two input formats and generic header lines.

Header lines The optional header lines specify generic information that apply to the partition table. The header-line format is:

<name>: <value>

The currently recognized headers are:

unit Specify the partitioning unit. The only supported unit is sectors.

label Specify the partition table type. For example dos or gpt.

label-id Specify the partition table identifier. It should be a hexadecimal number (with a 0x prefix) for MBR and a UUID for GPT.

first-lba Specify the first usable sector for GPT partitions.

last-lba Specify the last usable sector for GPT partitions.

table-length Specify the maximal number of GPT partitions.

grain Specify minimal size in bytes used to calculate partitions alignment. The default is 1MiB and it's strongly recommended to use the default. Do not modify this variable if you're not sure.

sector-size Specify sector size. This header is informative only and it is not used when sfdisk creates a new partition table, in this case the real device specific value is always used and sector size from the dump is ignored.

Note that it is only possible to use header lines before the first partition is specified in the input.

Unnamed-fields format start size type bootable

where each line fills one partition descriptor.

Fields are separated by whitespace, comma or semicolon possibly followed by whitespace; initial and trailing whitespace is ignored. Numbers can be octal, decimal or hexadecimal; decimal is the default. When a field is absent, empty or specified as '-' a default value is used. But when the -N option (change a single partition) is given, the default for each field is its previous value.

The default value of start is the first non-assigned sector aligned according to device I/O limits. The default start offset for the first partition is 1 MiB. The offset may be followed by the multiplicative suffixes (KiB, MiB, GiB, TiB, PiB, EiB, ZiB and YiB) then the number is interpreted as offset in bytes.

The default value of size indicates "as much as possible"; i.e., until the next partition or end-of-device. A numerical argument is by default interpreted as a number of sectors, however if the size is followed by one of the multiplicative suffixes (KiB, MiB, GiB, TiB, PiB, EiB, ZiB and YiB) then the number is interpreted as the size of the partition in bytes and it is then aligned according to the device I/O limits. A '+' can be used instead of a number to enlarge the partition as much as possible. Note '+' is equivalent to the default behaviour for a new partition; existing partitions will be resized as required.

The partition type is given in hex for MBR (DOS) where 0x prefix is optional; a GUID string for GPT; a shortcut or an alias. It's recommended to use two letters for MBR hex codes to avoid collision between deprecated shortcut 'E' and '0E' MBR hex code. For backward compatibility sfdisk tries to interpret type as a shortcut as a first possibility in partitioning scripts although on other places (e.g. --part-type command) it tries shortcuts as the last possibility.

Since v2.36 libfdisk supports partition type aliases as extension to shortcuts. The alias is a simple human readable word (e.g. "linux").

Since v2.37 libfdisk supports partition type names on input, ignoring the case of the characters and all non-alphanumeric and non-digit characters in the name (e.g. "Linux /usr x86" is the same as "linux usr-x86").

Supported shortcuts and aliases:

L - alias 'linux' Linux; means 83 for MBR and 0FC63DAF-8483-4772-8E79-3D69D8477DE4 for GPT.

S - alias 'swap' swap area; means 82 for MBR and 0657FD6D-A4AB-43C4-84E5-0933C84B4F4F for GPT

Ex - alias 'extended' MBR extended partition; means 05 for MBR. The original shortcut 'E' is deprecated due to collision with 0x0E MBR partition type.

H - alias 'home' home partition; means 933AC7E1-2EB4-4F13-B844-0E14E2AEF915 for GPT

U - alias 'uefi' EFI System partition, means EF for MBR and C12A7328-F81F-11D2-BA4B-00A0C93EC93B for GPT

R - alias 'raid' Linux RAID; means FD for MBR and A19D880F-05FC-4D3B-A006-743F0F84911E for GPT

V - alias 'lvm' LVM; means 8E for MBR and E6D6D379-F507-44C2-A23C-238F2A3DF928 for GPT

The default type value is linux.

The shortcut 'X' for Linux extended partition (85) is deprecated in favour of 'Ex'.

bootable is specified as [*|-], with as default not-bootable. The value of this field is irrelevant for Linux - when Linux runs it has been booted already - but it might play a role for certain boot loaders and for other operating systems.

Named-fields format This format is more readable, robust, extensible and allows specifying additional information (e.g., a UUID). It is recommended to use this format to keep your scripts more readable.

[device :] name[=value], ...

The device field is optional. sfdisk extracts the partition number from the device name. It allows specifying the partitions in random order. This functionality is mostly used by --dump. Don't use it if you are not sure.

The value can be between quotation marks (e.g., name="This is partition name"). The currently supported fields are:

start=number The first non-assigned sector aligned according to device I/O limits. The default start offset for the first partition is 1 MiB. The offset may be followed by the multiplicative suffixes (KiB, MiB, GiB, TiB, PiB, EiB, ZiB and YiB) then the number is interpreted as offset in bytes.

size=number Specify the partition size in sectors. The number may be followed by the multiplicative suffixes (KiB, MiB, GiB, TiB, PiB, EiB, ZiB and YiB), then it's interpreted as size in bytes and the size is aligned according to device I/O limits.

bootable Mark the partition as bootable.

attrs=string Partition attributes, usually GPT partition attribute bits. See --part-attrs for more details about the GPT-bits string format.

uuid=string GPT partition UUID.

name=string GPT partition name.

type=code A hexadecimal number (without 0x) for an MBR partition, a GUID for a GPT partition, a shortcut as for unnamed-fields format or a type name (e.g. type="Linux /usr (x86)"). See above the section about the unnamed-fields format for more details. For backward compatibility the Id= field has the same meaning.